osi cleveland



Nov. 26, 1 929. R -B F- Re. 17,499

POPPET VALVE Original Filed Aug. 2, 1926 //v l/E/wvz- 190/420 55/522;

BY v.-

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01110, Assmnoa 'ro rnoursou reass ss, me,

or cnnvnnann, care, a coaronarron or omo rorrn'r VALVE Original No.1,815,211 dated January 25, 1927, Serial reissue filed January 28, 1929.Serial No. 835,333.

This invention relates to valves such as are employed in internalcombustion engines, commonlyreferred. to as poppet valves, and moreparticularly to exhaust valves.

Such valves consist of a head provided with a seat fitted accurately tothe seat of an ex-,

haust port of the engine cylinder and a stem having "a sliding bearingin a part of the engine structure. The valve is ordinarily pressed toits seat by a strong, spring. In order to lift it from its seat topermitpassage of exhaust gases ,a tappet rod or arm is mounted for engagementwith the end of the stem, the ta or periodical engagement there- 7 with.The valve head and stem are subjected to conditions of heat which varywith the speed of the engine and other conditions. In the ordinaryconstruction the valve stem expands as the temperature rises and its endmoves toward the tappet. While there are other features which tend tomove the end of the stem in the opposite. direction such movement ismuch less than the movement toward the tappet. Therefore, unlessconsiderable clearance is provided between. the end of the stem and thetappet when the engine is cold or running under light load the expansionof the stem when the engine is hot will lift the valve from its seat. Asthis condition must necessarily be avoided the re' quired clearance isprovided, in consequence of which a great deal of noise results fromsuch a loose connection except when the em gine is hot. The idealconditionwould be that in which the expansion of the valve iscompensated for at all engine temperatures, thus permitting the sameclearance at all stages of engine operation.

The object of this invention is to remove or substantially reduce thenoise incident to such a loose connection between the tappet and valvestem. y

The attainment of this object has been at tempted heretoforeby employingspecial alloys for the stem or portions thereof having a coeflicient ofexpansion difl'ering from that of the head or other portions of thestem, but such means has been found unsatis- ,factory pet beingassociated-with a ro- By utilizing a difl'erent principle I have muchmore effectively The new principle involves expanding or mechanicallystressing the head and causing it to ride upon its tapered seatsufliciently No. 126,853, filed Augnst2,-1928.' Application for attainedthis object.

to draw the stem longitudinally to substantially the same extent thatits length increases with each increment of temperature. This Iaccomplish by providing the head with an insert of material having agreater coefiicient of expansion than the main body of the head, wherebythe whole head is enlarged in diameter but within the elastic limit.

or the purpose of exemplifying the prin ciple of the invention, Idisclose herein, one form inwhich I have embodied and tested theinvention, which is the best form now'known to me.

In the annexed drawings:

Figure l is a vertical sectional view through the engine structure inwhich my invention has been embodied, showing my valve in sideelevation.

Figure 2 is an elevation of the valve alone showing the head incross-section.

. My novel valve is shown in the, drawings as forming part of an eightcylinder overhead valve structure of an old and well own construction,so that it is unnecessary to describe in detail any of the enginefeatures.

In accordance with my improvement I provide a valve head 1 of well knownform with an insert 2 of material having a highercoefiicient ofexpansion than the main body of the head. The material selected for theinsert will depend upon the nature of the ma main body of the head andof the terial of the stem, upon the relatiye proportion of the head andinsert, upon the degree of taper to the valveseat, and

of the cooling medium thereto. the materials of the valve head culated=for' each engine structure.

must be calupon the characteristics of the engine structure andof therelation Ordinarily engineof' the construction shown: in the 'draw ings,I 'havle found an efiicient'embodiriientof my invention afvalvemaldeofthe folldw ing mat r als edrr e iq s 1 subject nickel, said inserthaving a member comprism a of insert-alloy steel:

12.0; S1, 2.0; Ni, 7.5; iron 78.15.

valve head and'stem-alloy Composition "0., 0.35; On, and impurities,

Composition of steel:

C, 0.45; Cr., 8.25; Si.,.3.25; iron and impurities, 88.05.

The coefiicient of expansion of an insert of such composition is .000010inch per degree F. and of the valve head and stem .00000703 inch perdegree F.

The fabrication of the valve head may be effected in difl'erent ways,but I have discovered an economical and effective process for producingsuch a product, which forms the matter of a concurrently filedapplication, Serial No. 126,355. Briefly described this process consistsin forming a recess in the upper en valve head and stem, filling therecess either partially or wholly with the material of the msert, andthen upsetting the end in suitable dies according to known practice,whereby the head is flattened, and the material of the blank is causedto-surround, in whole or in part, the material of the insert. A

While I have described but one embodiment of the invention, it isobvious that the materials may be varied for the same situation and thatdifferent situations or engine structures require'changes to meet theparticular conditions. It istherefore to be understood that thedisclosure herein is merely exemplary of the principle involved and thatmy invention comprehends all changes and modifications falling withinthe terms of the appended claims.

What I.claim is:

1. As an article of manufacture, a valve head provided with a taperedseat and an insert having a greater coeflicient of expansion than themam body of the head, adapted to compensate for the extension of thevalve stem due to increasin temperatures.

2. As an article 0 manufacture, a valve head having a ta body portion iso silicon chromium steel provided with an insert of alloy steelcontaining eater coefiicient of expansion than the main ody of the head.

3. In combination with an internal combustion engine having an exhaustport with a tapered seat, a poppet valve with a ta seat fitting into thetapered seat of the ex aust port, the head of the valve being providedwith an msert of material having a coeflicient of expansion greater thanthe main body of the head.

' 4. As an article of manufacture, a headed stem, a head thereon, and aninsert in sai head of a material having a coeflieient of expansiongreater than that of the head proper for compensating for the expansion0 'a portion of said member.

5. As an article of manufacture, a headed d ofa blank adapted to formthe ered'seat and whose main ered member comprising a stem, a headthereon, and an insert of alloy steel containing nickel in said headhaving a coeflicient of expansion greater thanthat of the head properfor compensating for the expansion ofa portion of said member.

6. As an article of manufacture, a headed member comprisin a stem, .ahead thereon including a tapere seat portion, and an insertin said headhaving a greater coeflicient of expansion than that of the head properand arranged to compensate for the extension of the stem due toincreasing temperatures.

7. As an article of manufacture, a headed member comprising a stem, ahead thereon, and an insert in .said head separate from the head andstem and possessing characteristics different from that of the headproper and which has been flattened and interlocked with the head duringthe forming of the head.

8. As an article of manufacture, member comprising a stem, a headthereon, and an insert disposed wholly within said head including arelatively thin lateral pora headed 5 tion extending toward theperipheral edge of said head and which has been interlocked

